{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-90039",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-09-11T19:38:34.783Z",
        "datePublished": "2026-09-16T10:33:38.091Z",
        "dateUpdated": "2026-10-19T08:56:56.714Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-10-19T08:56:56.714Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nNFSD: Guard admin state-revocation walks with NFSD_NET_UP\n\nWriting to /proc/fs/nfsd/unlock_filesystem, or sending the\nNFSD_CMD_UNLOCK_FILESYSTEM or NFSD_CMD_UNLOCK_EXPORT netlink command,\nwalks the NFSv4 client hash tables to revoke open state and cancel\nasync COPY operations.  All three handlers gate that walk on\nnn->nfsd_serv, but a listener added via portlist or netlink\nlistener_set sets nn->nfsd_serv before any nfsd thread starts.\nnfsd_startup_net() has not yet allocated nn->conf_id_hashtbl, so the\nwalkers dereference a NULL table.  A local administrator with\nCAP_SYS_ADMIN can crash the kernel this way without ever starting the\nserver.\n\nnn->nfsd_serv is set when the service is created, which precedes\ntable allocation.  NFSD_NET_UP instead brackets the window where the\ntables are live: set at the end of nfsd_startup_net() and cleared in\nnfsd_shutdown_net() after they are freed, both under nfsd_mutex.\nGating the three unlock paths on NFSD_NET_UP fixes the startup-time\nNULL dereference while preserving the earlier post-shutdown\nuse-after-free fix."
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "fs/nfsd/nfs4proc.c",
                        "fs/nfsd/nfs4state.c",
                        "fs/nfsd/nfsctl.c"
                    ],
                    "versions": [
                        {
                            "version": "1ac3629bf012592cb0320e52a1cceb319a05ad17",
                            "lessThan": "73bf459d696ecf207a9037bf9bb70c51a459469e",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "1ac3629bf012592cb0320e52a1cceb319a05ad17",
                            "lessThan": "104a51265042b4424085741c963cb858ac29ec0b",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "1ac3629bf012592cb0320e52a1cceb319a05ad17",
                            "lessThan": "0146467a2fce845cb6629979c3e9c58dd3d3a6a3",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "1ac3629bf012592cb0320e52a1cceb319a05ad17",
                            "lessThan": "2f3e6638aebc0ab8afb8b4e9816ea9a1cad85378",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "fs/nfsd/nfs4proc.c",
                        "fs/nfsd/nfs4state.c",
                        "fs/nfsd/nfsctl.c"
                    ],
                    "versions": [
                        {
                            "version": "6.9",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "6.9",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.111",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.51",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.2.5",
                            "lessThanOrEqual": "7.2.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.3",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }
            ],
            "cpeApplicability": [
                {
                    "nodes": [
                        {
                            "operator": "OR",
                            "negate": false,
                            "cpeMatch": [
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.9",
                                    "versionEndExcluding": "6.12.111"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.9",
                                    "versionEndExcluding": "6.18.51"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.9",
                                    "versionEndExcluding": "7.2.5"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.9",
                                    "versionEndExcluding": "7.3"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/73bf459d696ecf207a9037bf9bb70c51a459469e"
                },
                {
                    "url": "https://git.kernel.org/stable/c/104a51265042b4424085741c963cb858ac29ec0b"
                },
                {
                    "url": "https://git.kernel.org/stable/c/0146467a2fce845cb6629979c3e9c58dd3d3a6a3"
                },
                {
                    "url": "https://git.kernel.org/stable/c/2f3e6638aebc0ab8afb8b4e9816ea9a1cad85378"
                }
            ],
            "title": "NFSD: Guard admin state-revocation walks with NFSD_NET_UP",
            "x_generator": {
                "engine": "bippy-1.2.0"
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        }
    }
}